Fans and critics alike can’t seem to get enough of Beyonce’s new visual album, but one song is being criticized by an unexpected group.

In the song “XO,” the singer uses an audio clip from the day the Challenger space shuttle exploded in January 1986. “Flight controls here looking very carefully at the situation,” then-NASA public affairs officer, Steve Nesbitt, says in the voiceover. “Obviously a major malfunction.”

Current/former NASA employees, as well as surviving family members of the tragedy’s victims, are calling the audio use “insensitive.” Beyonce released a statement following the backlash on Monday.

“My heart goes out to the families of those lost in the Challenger disaster,” she said. “The song “XO” was recorded with the sincerest intention to help heal those who have lost loved ones and to remind us that unexpected things happen, so love and appreciate every minute that you have with those who mean the most to you. The songwriters included the audio in tribute to the unselfish work of the Challenger crew with hope that they will never be forgotten.”

On Dec. 13, the 32-year-old released her self-titled album, including 14 songs and 17 videos, without any warning on iTunes. It debuted at No. 1 on the Billboard charts, and already sold more than 1,000,000 copies worldwide.